Analyzers for dispensing a sample and a reagent into a reaction container and measuring absorbance of a reaction liquid produced in the reaction container to analyze the sample have been conventionally known. Such an analyzer comprises a photometry section having a light source and a light receiving section. The light source irradiates light onto the reaction container containing the reaction liquid, and the light receiving section calculates the absorbance based on the amount of light transmitted through the reaction liquid in the reaction container and received by the light receiving section, to analyze the sample.
One of the methods for calculating absorbance is as follows: every time a reaction container passes through a photometry section, the photometry section successively irradiates light onto a plurality of measurement points on the reaction container, and the photometry section receives the light transmitted through the reaction liquid and averages the received light, thereby calculating the absorbance of the reaction liquid. Through this method, it is possible to prevent variations in the amount of light for each measurement point used to calculate absorbance. However, if there is a measurement point at which a sample and a reagent are not mixed with each other sufficiently, or if there is a measurement point at which a foreign matter or the like is mixed in the reaction liquid, then the light to be transmitted through the reaction liquid is blocked due to such a measurement point. As a result, there have been cases where the amount of light at this measurement point is reduced and absorbance is thus calculated to be a value higher than the actual value.
Thus, another analyzer is known, for excluding absorbance measurement data considered as an erroneous measurement from subjects to be analyzed and conducting an analysis by using only absorbance measurement data having high reliability.
An analyzer for excluding a conspicuous amount of light at a measurement point, different from ordinary amounts of light of chemical reactions at a plurality of measurement points, is described in Patent Document 1, for example.
An analyzer for measuring absorbance data at a plurality of measurement points, calculating an absorbance data change rate with regard to the plurality of measurement points, and excluding absorbance data whose absorbance data change rate is outside the acceptable range, is described in Patent Document 2, for example.
An analyzer for measuring absorbance data at a plurality of measurement points, calculating a standard deviation of an absorbance data change rate regarding the plurality of measurement points, distinguishing a reaction container having a scratch or stain by using the calculated standard deviation, and excluding the absorbance data of the reaction container, is described in Patent Document 3, for example.
These analyzers are for excluding absorbance measurement data considered as erroneous measurements from subjects to be analyzed; however, they are not capable of detecting an overflow of a liquid. Furthermore, with conventional methods for detecting a liquid overflow, it has been necessary to set up an additional detection apparatus.